L3 Project Build Thread - Performance Rocketry Competitor 4

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AlnessW

AlnessW

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I got my L2 this past year. As the 2013 season came to a close I knew I wanted to try a fiberglass build this winter. I figured this would be a great opportunity to go for 75mm as well, which led me to believe that this would be an ever better opportunity for an L3 project.

Did a bit of shopping around for kits and Performance Rocketry or Wildman seemed like a great choice. I almost went for the Intimidator 4, but opted for a Competitor 4 as I liked the look of the fins a bit better.

I didn’t have the think twice about who I was going to ask to be TAPs. Fred Azinger and David Holloway were both OregonRocketry members and had known me for a long time. After their initial approval of the project, I had Mike at Bay Area Rocketry order the kit from Wildman and he had it shipped directly to me. Thanks Mike!

IMG_1834a.jpg

When I opened the big box I was a bit surprised to discover that the kit came in black fiberglass. Mike explained to me that the color of the FG can simply very to kit to kit, so I wasn’t too concerned. Another thing that came as a bit of surprise was that the kit didn’t come with instructions. Luckily though, after I made my first few sketches, I was relieved to discover that I did in fact know what the heck I was doing.

After reviewing my first sketch, Fred pointed out that with the stock kit design, my parachute bays would be quite small. The booster section was 44” long and the main section was 22” long. A 22” main bay – minus about 12” from the couplers – would leave me with… 10” of compartment space for the main chute and harness? Yikes. Being the excellent coach that he is, Fred suggested a different design. This would make the rocket about 1.5’ longer, and also “zipperless.” The plan was to cut the 44” booster section down to 28”, glue in an extra coupler/bulkhead, and use the 22” main section for the drogue. Then get a new 36” piece of fiberglass tube for the main section. Perfect.

Fiberglass parts clean and freshly washed:
IMG_1848a.jpg

Yesterday I went over to West Marine and got the epoxy I needed to start the build:
IMG_1849a.jpg

I mixed a test batch of epoxy last night and was impressed this morning at how strong it cured! No doubt this stuff is rated for fiberglass. Going to glue the first joints later today!
 
AlnessW said:
I got my L2 this past year. As the 2013 season came to a close I knew I wanted to try a fiberglass build this winter. I figured this would be a great opportunity to go for 75mm as well, which led me to believe that this would be an ever better opportunity for an L3 project.

Did a bit of shopping around for kits and Performance Rocketry or Wildman seemed like a great choice. I almost went for the Intimidator 4, but opted for a Competitor 4 as I liked the look of the fins a bit better.

I didn’t have the think twice about who I was going to ask to be TAPs. Fred Azinger and David Holloway were both OregonRocketry members and had known me for a long time. After their initial approval of the project, I had Mike at Bay Area Rocketry order the kit from Wildman and he had it shipped directly to me. Thanks Mike!

View attachment 154247

When I opened the big box I was a bit surprised to discover that the kit came in black fiberglass. Mike explained to me that the color of the FG can simply very to kit to kit, so I wasn’t too concerned. Another thing that came as a bit of surprise was that the kit didn’t come with instructions. Luckily though, after I made my first few sketches, I was relieved to discover that I did in fact know what the heck I was doing.

After reviewing my first sketch, Fred pointed out that with the stock kit design, my parachute bays would be quite small. The booster section was 44” long and the main section was 22” long. A 22” main bay – minus about 12” from the couplers – would leave me with… 10” of compartment space for the main chute and harness? Yikes. Being the excellent coach that he is, Fred suggested a different design. This would make the rocket about 1.5’ longer, and also “zipperless.” The plan was to cut the 44” booster section down to 28”, glue in an extra coupler/bulkhead, and use the 22” main section for the drogue. Then get a new 36” piece of fiberglass tube for the main section. Perfect.

Fiberglass parts clean and freshly washed:
View attachment 154243

Yesterday I went over to West Marine and got the epoxy I needed to start the build:
View attachment 154242

I mixed a test batch of epoxy last night and was impressed this morning at how strong it cured! No doubt this stuff is rated for fiberglass. Going to glue the first joints later today!
Click to expand...

If you look at test data, you'll see that for maximum strength cure time is 2 weeks. I too use west systems, but I have heard that Aeropoxy is a little bit stronger.
 
FWIW, I only use the Aeropoxy products. I've had great success and have found the tech support on the products to be excellent on those occasions when I've had questions.
 
dward said:
If you look at test data, you'll see that for maximum strength cure time is 2 weeks. I too use west systems, but I have heard that Aeropoxy is a little bit stronger.
Click to expand...

Ultimate strength at room temperature is one thing.

But Aeropoxy has a much higher glass transition temperature; West softens at 120 F.

As in: a hot day will significantly weaken West Systems. West is made for boats: it's completely waterproof, and boats usually don't have to worry about heat too much.
 
CarVac said:
Ultimate strength at room temperature is one thing.

But Aeropoxy has a much higher glass transition temperature; West softens at 120 F.

As in: a hot day will significantly weaken West Systems. West is made for boats: it's completely waterproof, and boats usually don't have to worry about heat too much.
Click to expand...

Carlo,

Please stop pooping on West Systems' Cheerios! We know that you are the poster boy for Aeropoxy products; but please understand there are other products out on the market that will do the job just fine!

Wilson; your West 105/205 is an excellent purchase for your application! In fact, I did my L3 with a Competitor4 built with West Systems in April of 2005. After 10 L/M flights, I retired the bird (it's functionally fine but decided to retire it before I lose it for sentimental reasons:wink:)

While I am not an expert on epoxy, I have put the following products through the ringer: UsComposites (2:1, 3:1), Proline 4100, Proline 4500, West Systems 105-205/206/207, Aeropoxy lam, Rocketpoxy, Bob Smith, Zap, Cotronics 4461 (and another # I can't remember off the top of my head, and several other Hobby grade epoxies. All have their pluses and minuses. Most will work just fine for what we do.

I've been flying rockets year round; both in the extremes of warm and cold for 20 years, with rockets largely assembled with West Systems products up to mach 2.7 and my go-to choice is still West System. Real world experience always trumps numbers in a theoretical world!

-Eric-
 
I use both West and Aeropoxy. Never had any failures launching on hot Florida days in July. Had a Mad Cow Frenzy come down HARD after a main hung up in the payload tube and the fins held - West mixed with fillers was used for the fillets and Aeropoxy 6209 was used on the fin root to MMT bond. The tube buckled a bit between the split fins due to the impact, but the fins held! It still flies on J motors just fine.

My only epoxy related failures have been DevCon epoxy - cracked fillets and a fin root that came unbonded from the motor tube after about five flights and easy landings.
 
For what it is worth, I built the Competitor 4 using LOCTITE 5 minute epoxy from Home Depot. I have flown it on an L-850 and on an M-1315 twice. Best flight hit 13,835 feet and everything is holding together just fine. Fantastic kit, and it will make a great L3 project.
 
Hi everyone, sorry to drop off the earth on you for a few days. Been having difficulties with the TRF site.

chuck5395 said:
Awesome Wilson. I'll be watching your build with great interest.
Click to expand...
Thank you for the kind words, Chuck!

jackman said:
FWIW, I only use the Aeropoxy products. I've had great success and have found the tech support on the products to be excellent on those occasions when I've had questions.
Click to expand...
Hi Gary - yes, Aeropoxy seems to be a popular choice around here. Good advice!

ECayemberg said:
Wilson; your West 105/205 is an excellent purchase for your application! In fact, I did my L3 with a Competitor4 built with West Systems in April of 2005. After 10 L/M flights, I retired the bird (it's functionally fine but decided to retire it before I lose it for sentimental reasons:wink:)
Click to expand...
Thanks Eric! Just like your Comp 4, I have heard good things about rockets built with West Systems.

rockethead said:
For what it is worth, I built the Competitor 4 using LOCTITE 5 minute epoxy from Home Depot. I have flown it on an L-850 and on an M-1315 twice. Best flight hit 13,835 feet and everything is holding together just fine. Fantastic kit, and it will make a great L3 project.
Click to expand...
Very cool! I assume it was the M1315W that sent it up to almost 14K?

emckee said:
:pop:

Any idea when you'll be launching? NXRS?
Click to expand...
Hi Erik - yes, I am planning on certifying at NXRS after doing a few checkride flights on K's and L's in May/June if possible. You're not the first person to "request" NXRS. ;)
 
Over the past few days I have tacked and epoxied the forward and middle centering rings in place.

IMG_1853a.jpgIMG_1855a.jpg
 
Wait a minute!
All fiberglass build threads must start with a picture of the parts soaking in the bath tub.
 
chuck5395 said:
Wait a minute!
All fiberglass build threads must start with a picture of the parts soaking in the bath tub.
Click to expand...

LOL - Must have forgotten that photo somehow! ;) I did however do a soak, scrub and IPA wash.
 
AlnessW said:
... After reviewing my first sketch, Fred pointed out that with the stock kit design, my parachute bays would be quite small. The booster section was 44” long and the main section was 22” long. A 22” main bay – minus about 12” from the couplers – would leave me with… 10” of compartment space for the main chute and harness? Yikes. ...
Click to expand...

IIRC, the coupler is about 11 inches long, and the nosecone shoulder somewhere close to 4". On a conventional build, half the coupler would be in the lower tube, so it takes out 5.5". So the available tube for recovery is 22" - (5.5" + 4") = 12.5". Some of this is taken by bulkhead, etc.

I have found that space to be fully sufficient for recovery packing in an equivalent rocket. But kit bashing is more fun anyway!

Gerald
 
G_T said:
IIRC, the coupler is about 11 inches long, and the nosecone shoulder somewhere close to 4". On a conventional build, half the coupler would be in the lower tube, so it takes out 5.5". So the available tube for recovery is 22" - (5.5" + 4") = 12.5". Some of this is taken by bulkhead, etc.

I have found that space to be fully sufficient for recovery packing in an equivalent rocket. But kit bashing is more fun anyway!

Gerald
Click to expand...

Hi Gerald, yes - I believe those figures are correct. You are exactly right about the "kit bashing," in fact I wasn't sure if I wanted to do a scratch build versus a kit for my L3. But by buying a kit and modifying it slightly, this was the perfect combination!
 
Well it's about time I updated you all. First off, Fred Azinger has recently (within the past few weeks) stepped down as a TAP. Luckily though, I heard from many other TAPs in the area, all of which were willing to help out. I decided to go with Jack Garibaldi at What's Up Hobbies since he often attends OROC launches. It was very reassuring to know that I was in good hands!

I just ordered some 3-piece 1010 rail buttons from rail-buttons.com, along with a couple bags of 4-40 nylon screws for shear pins. I also bought a few parts I needed for the build from Jack - a 24" SkyAngle Cert-3 drogue chute, a 12" coupler, and some shockcord material. I'll post photos of everything soon, but for now I just wanted to update you all having disappeared for almost a month. :(

I also went over to the "Team Hardtail headquarters" (Fred's team - the pole barn at Gabe and Vicki's house) last weekend to cut the booster section down to 28" for the zipperless design I'll be using. Stay tuned...
 
Just a thought... 1010 rail sounds rather filmsy. Is the rail supported by means of a tower, or the conventional adapter (to slip into a standard screw-in-place pad)? If by a tower of some sort, cool. If not, you may want to reconsider.. You may be introducing some serious rod whip (I have a 3" rocket that I'm about to put a K1275 in and I don't want to hinder performance/safety by going with a 1010 rail so I installed a set of 1515's on the opposite side of the bird).

Just thought I might mention this food for thought.
 
mrwalsh85 said:
Just a thought... 1010 rail sounds rather filmsy. Is the rail supported by means of a tower, or the conventional adapter (to slip into a standard screw-in-place pad)? If by a tower of some sort, cool. If not, you may want to reconsider.. You may be introducing some serious rod whip (I have a 3" rocket that I'm about to put a K1275 in and I don't want to hinder performance/safety by going with a 1010 rail so I installed a set of 1515's on the opposite side of the bird).

Just thought I might mention this food for thought.
Click to expand...

Fred told me not to bother with 1515 as he has flown much bigger rockets than mine off 1010 rails. If it makes a difference, I am installing 3 buttons instead of 2. With regards to the pad configuration, I am planning on doing a "checkride" flight on an L850W early next season, and this flight would be off a traditional rail and pad. For the L3 flight I will be using a bigger, stronger pad with a larger base and extra support. Again, I've seen MUCH bigger rockets than mine fly off this particular pad with no issue. Unless of course, someone offers me a tower to use.
 
Wilson, you are only a few weeks into this project and you've already raised two controversies! Epoxy and Rail Button Size! Well played, man.

You can use my tower when the time comes.

David
 
1010 buttons will work on a 1515 rail. The fit is a little loose, but they won't fall out of the rail. I've flown a 4 inch rocket this way a couple times.
 
David said:
Wilson, you are only a few weeks into this project and you've already raised two controversies! Epoxy and Rail Button Size! Well played, man.

You can use my tower when the time comes.

David
Click to expand...
Indeed, I have! Thank you for the kind words and the tower offer. As per my previous post, I had planned on using Quadzilla unless I get a better offer! :)

MarkH said:
1010 buttons will work on a 1515 rail. The fit is a little loose, but they won't fall out of the rail. I've flown a 4 inch rocket this way a couple times.
Click to expand...
Good to know!
 
You are cutting the fincan down to 28in & making it zipperless, how long a 75mm case are you using on your attempt?
By cutting it down you are seriously limiting the range of motors you will be able to fly.[unless I'm missing something here?]

I'm totally lost on the reasoning with this one. I have one of the first Comp 4's made, it's flown on anything you can imagine up to 7600 cases [had to use a band to get that in, the coupler was 1/2 too long.LOL] I have stuffed 72in chute, 96in chute, [72 & 60 both] with 27 ft of 9/16 TN..... never had any issues with getting it all in.

If you are concerned, just move the NC bulkplate up to top of shoulder & gain 6 more inches of space. Or replace the bolt holding the metal tip on with a eyebolt..... then you have the entire NC for excess recovery gear. There are so many options besides cutting down the fincan.

I also have just 2 1010 buttons on it. 3 will tend to bind & are really not needed. 1010 buttons are rated for use up to 75lbs by the way.
 
blackjack2564 said:
You are cutting the fincan down to 28in & making it zipperless, how long a 75mm case are you using on your attempt?
By cutting it down you are seriously limiting the range of motors you will be able to fly.[unless I'm missing something here?]

I'm totally lost on the reasoning with this one. I have one of the first Comp 4's made, it's flown on anything you can imagine up to 7600 cases [had to use a band to get that in, the coupler was 1/2 too long.LOL] I have stuffed 72in chute, 96in chute, [72 & 60 both] with 27 ft of 9/16 TN..... never had any issues with getting it all in.

If you are concerned, just move the NC bulkplate up to top of shoulder & gain 6 more inches of space. Or replace the bolt holding the metal tip on with a eyebolt..... then you have the entire NC for excess recovery gear. There are so many options besides cutting down the fincan.

I also have just 2 1010 buttons on it. 3 will tend to bind & are really not needed. 1010 buttons are rated for use up to 75lbs by the way.
Click to expand...

Right, the booster section is 28" long, plus 6" of coupler, for an overall length of 34". The Rouse-Tech 75/5120 case that houses the M1297W is 26" long. The next motor size up, the 75/6400 case (M1315W), is 31" long. If I were to put a 31" motor in the original 44" long booster, it would leave me with about 13" of space for a drogue, minus 6" for the coupler. Seems tight to me!
 
IMG_1857a.jpgIMG_1856a.jpgIMG_1858a.jpg

Package in the mail from Randy at www.rail-buttons.com - a bag of 3-piece 1010 nylon rail buttons, and 2 bags of 4-40 nylon screws. He even threw in a free pair of 3-piece Delrin buttons and a "Thank you" mint! :)

While waiting to cut the piece of airframe I began construction on the av-bay. First I glued and drilled the bulkplates, then I cut 2 x 1/4" all-thread rods to length. It all goes together quite nicely. Next up - forged eyebolts and attaching the switch band.
 
Nice rocket by the way and as Jim says two 1010 buttons are plenty. Have fun
 
Looking good Wilson. At least one of us is moving forward with our planned winter projects.
 
neond7 said:
I agree that three buttons provide better guidance. As soon as the first rail button comes off the rail, that rear button isn't doing much.....
Click to expand...

Wouldn't the same thing be accomplished by moving the forward button down on the rocket? Of course, then you lose something by having the buttons closer together, but it seems like getting three buttons in a straight line could be a challenge (at least within the tolerances allowed by the rail slot width).

Would love to hear about your technique for lining them all up when you get there.
 
emckee said:
Wouldn't the same thing be accomplished by moving the forward button down on the rocket? Of course, then you lose something by having the buttons closer together, but it seems like getting three buttons in a straight line could be a challenge (at least within the tolerances allowed by the rail slot width).

Would love to hear about your technique for lining them all up when you get there.
Click to expand...

Honestly, I only have three buttons on one of my rockets, I haven't decided if I'll be putting three on my level 3 build. I will use wood backing blocks attached to the upper and bottom centering rings with brass inserts for two of them. The middle one (if I go that route) will just be drilled into the airframe and epoxied on.

As far as installation technique for the third button, its pretty easy. I just use a long piece of angle iron and butt it up against the upper and lower buttons. Then I place the third button against the angle iron and hold it in place while I drill the pilot hole. Since all three buttons are physically aligned with the angle iron, they will be straight and not bind. Trying to eyeball them in place would be asking for trouble.
 

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